Association between intake of the n-3 polyunsaturated fatty acid docosahexaenoic acid (n-3 PUFA DHA) and reduced risk of ovarian cancer: A systematic Mendelian Randomization study.

BACKGROUND & AIMS: Whether the intake of docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid, is beneficial for ovarian cancer (OC) remains controversial and we hope to disentangle this puzzle using genetic data from large-scale populations in European and Asian. METHODS: We employed, for the first time, a systematic Mendelian randomization (MR) design to comprehensively evaluate the causal effect of plasma DHA levels, an objective biomarker of DHA intake, on OC risk in European and then verified the extrapolation of the results in the Asian. Data in the analysis included genetic association data obtained from large-scale genome-wide association studies with 13,499 individuals for plasma DHA measurements and 66,450 individuals for OC in the European population, and 1361 individuals for plasma DHA measurements and 61,457 individuals for OC in the Asian population. The causal relationship between DHA and OC was estimated using the inverse-variance weighted approach, together with extensive validation and sensitivity analyses to verify the main results. RESULTS: In the European population, MR evidence suggested a causal relationship between higher plasma DHA levels and lower OC risk (OR, 0.89 for OC per one-SD increment in DHA; 95% CI, 0.83 to 0.96; P = 0.003). Subgroup analysis by histological type of OC indicated that this observed association was stronger among endometrioid ovarian cancer (EOC) (OR, 0.82; 95% CI, 0.69 to 0.96; P = 0.014). A similar causal association of borderline significance was reached in the Asian replication set. The above results were consistently supported by a series of validation and sensitivity analyses. CONCLUSION: Our study provided robust genetic evidence for a protective association between plasma DHA levels and lower risk of OC, especially EOC, in the European population. These findings may inform prevention strategies and interventions directed towards DHA intake and OC.

[Anti-oxidative effects of proanthocyanidins in mice induced by D-galactose].

The anti-oxidative effect of proanthocyanidins(PC) was evaluated in D-galactose-induced murine model. Male KUNMING mice were divided into different groups at random. The mice were induced by subcutaneous injection of D-galactose on the back of mice daily for 60 days and simultaneously PC and VE were administered to the mice by oral feeding. Results indicate that the lipid peroxide in blood, liver and brain significantly increased respectively because of the D-galactose injection, when compared to the control. The activity of SOD in RBC and liver significantly decreased while that of GSH-PX in blood and liver decreased. MAO-B in brain was significantly increased while MAO-B in liver doesn't change significantly. Oral feeding PC markedly decreased the formation of MDA in blood, liver and brain, increased the activities of SOD in blood and liver and decreased the activity of MAO-B in brain. Vitamin E also counteract the oxidative stress induced by D-galactose. In summary, treatment with PC at all the three tested doses were effective in exerting a protective effect against oxidative stress.